Rotary incorporator and spider wheel therefor

ABSTRACT

A rotary incorporator for one pass incorporation of chemicals or small grains in previously tilled soil. The incorporator includes two rows of aggressive, large diameter spider wheels supported from a toolbar for rotation in the soil about axes offset at an acute angle to the transverse direction. The spider wheels, arranged to balance the forces transmitted to the toolbar, are angled in opposite directions on each half portion of the implement, with the wheels of the trailing row angled in opposite direction to and offset transversely with respect to the forwardly adjacent wheels in the forward row. The innermost wheels of each of the two rows are more widely spaced and smaller in diameter than most of the remaining wheels, and two additional smaller diameter spider wheels are centrally located between the innermost wheels and cooperate therewith to provide good incorporation and a smooth seed bed without hilling or chemical banding. A smaller diameter, depth limited spider wheel on each outermost end of the implement feathers the effect of the angled wheels. The spider wheels include tines having a concave soil working surfaces for good mixing and soil moving action and a large gullet area for good trash shedding and throwing characteristics.

BACKGROUND OF THE INVENTION

The present invention relates generally to agricultural implements, andmore specifically, to implements for incorporating chemicals or smallgrains into the soil.

Chemicals have become widely used in the farming industry. Typically, achemical is applied to the surface of previously worked soil and amaximum of two additional tillage passes are made either with a disk orfield cultivator to incorporate the chemical into the upper few inchesof the soil. Although some farmers eliminate the recommended secondincorporation pass, they must rely on favorable weather conditions toprevent failure, and horizontal and vertical distribution patterns ofthe chemical often are much less than optimum. Although surface appliedchemicals are available at a higher cost, they are usually incorporatedby rainfall and there is a considerable amount of risk involved withsuch a chemical since rainfall is highly unpredictable. Often the costof chemicals which eliminate incorporation passes exceeds the combinedcost of the tillage and chemicals they replace.

Where two incorporation passes with a conventional tool are notnecessary, special harrows or S-tine cultivators have been devised foruse in one or more passes. These tools are limited to shallowincorporation of herbicides in low residue environments. Another popularapproach has been to combine the tillage of two passes into one pass bycombining the components of two conventional machines into one frame.However, the price and the draft are approximately doubled The advantageof making passes in different directions has been lost, and thereforestreaking and marginal performance are common with many of the availableincorporating devices. Combining tillage work also reduces theversatility of an implement. For example, if a late mechanical weed killis desired, all tillage must be done just prior to planting. This canrequire a very large tractor in order to stay ahead of a large modernplanter. Although disks and field cultivators can provide adequateincorporation in some circumstances, they generally require a highenergy consumption and a massive frame. Streaking or banding of thechemicals is common, particularly when a disk with large and widelyspaced disk blades is used. The operating speeds, and thus theproductivity, of these types of machines are often limited to beyond thelevel which is satisfactory to the farmer.

Although some rotary incorporating machines have been available on themarket, these have not been entirely satisfactory for one or morereasons. Some rotary hoe type of weeders having a single transverselyextending row of spider wheels have been utilized to incorporatepre-plant chemicals. However, these can only be used in certainconditions and where incorporation is not critical, or alternatively,where two passes of the rotary hoe are utilized. A single row of rotaryhoe spider wheels tends to cause the chemical to streak, leaving hotbands of chemical where crops can be damaged or destroyed while leavingother areas substantially void of chemicals. Often the spider wheelsdesigned for rotary hoeing to remove small weeds and break up surfacecrusts are not suitable for mixing soil. The tines of such hoes aretypically triangularly shaped with a principle design criteria beingeasy entry into the soil. Unless there is adequate depth control of thespider wheels, the wheels can act more like solid disks, pushing thesoil to one side rather than letting the soil flow through the tines andmix and incorporate the chemical. Other types of rotary incorporatorsuse two or more angled gangs of spider wheels spaced fore-and-aft withrespect to each other. Typically the forward gang is angled with respectto the transverse in an opposite direction as compared to the rearwardgang. Numerous pairs of the fore-and-aft spaced gangs are locatedtransversely along a large frame with adjacent gangs being angled inopposite directions with respect to the transverse to generally equalizeside forces along the width of the machine. In an implement where suchgangs are used, the area between adjacent gangs produces a discontinuityin the soil throwing and mixing action as compared with the actionwithin the confines of the gang itself. Also, the outermost wheels ofthe machine tend to throw dirt and chemical beyond the width of themachine so that there is ridging and chemical mixing variations adjacentthe edge of the machine. Although such machines may have improvedincorporation as compared with a conventional disk arrangement, amassive and expensive frame is necessary to support the gangs of spiderwheels. Therefore, such an implement is comparable in size and in priceto a disk or other conventional tillage implement.

Previously available rotary type incorporators often include tandem setsof spider wheels closely spaced fore-and-aft so that in trashyconditions the wheels may plug. Some arrangements utilize a wheelsupport arm closely spaced to the spider wheel, which also presents apotential clogging problem in trashy conditions. The spider wheelsthemselves often are of the type wherein the opening between the teethdecreases substantially in the direction toward the hub to thereby causewedging of trash. The tooth profile is often designed to provide easyentry into the soil rather than providing good cleaning characteristicswhich are necessary in heavy trash.

OBJECTS OF THE INVENTION

Therefore, it is an object of the present invention to provide animproved rotary incorporator for incorporating chemicals or small grainsinto previously tilled soil. It is another object of the invention toprovide an improved spider wheel for such an implement with bettermixing and trash-shedding characteristics than at least most previouslyavailable spider wheels.

It is a further object of the invention to provide a rotaryincorporating implement which effectively incorporates chemicals intothe soil in one pass as well as most conventional implements incorporatein two passes. It is a further object to provide such an implement whichuniformly incorporates chemicals across its entire width withoutstreaking and without leaving center or end ridges. It is yet anotherobject to provide such an incorporator having reduced draft and capableof high speed operation so that chemical can be applied just prior toplanting without incurring planter delay or large traction requirementsfor increased productivity and late mechanical weed kill.

It is still another object of the invention to provide an improvedrotary incorporator having a relatively compact and inexpensive frame.It is another object to provide such an incorporator having a balanceddesign with oppositely angled spider wheels which do not leave ridgesand wherein the side forces acting on the angled spider wheels areabsorbed and balanced by the spider wheel mounting arrangement.

It is yet another object of the invention to provide an improved rotaryincorporator with angled spider wheels having a spider wheelconfiguration which eliminates center ridges while providing uniformcenter incorporation and which feathers the effect of angled wheels atthe end of the machine. It is yet another object to provide such anincorporator which is able to operate in high levels of residue whileleaving a high percentage of existing residue on the surface of theground.

It is another object of the invention to provide a rotary chemicalincorporator having a draft requirement which is substantially less thanthat of conventional implements and yet is able to incorporate chemicalseffectively in one pass.

It is still another object of the invention to provide an improvedrotary incorporator spider wheel having improved mixing action,trash-shedding capability, and better depth control than at least mostof the previously available spider wheel configurations.

BRIEF SUMMARY OF THE INVENTION

The rotary incorporating implement constructed according to theteachings of the present invention includes a transverse beam supportinga plurality of spider wheel assemblies, each assembly including afore-and-aft extending drawbar pivotally connected at its forward end tothe frame for rocking vertically. An inverted U-shaped wheel supporthaving an upper transversely extending bight portion connected to theaft end of the drawbar includes downwardly directed side legs which eachcarry a spider wheel at the end. A first set of assemblies with shortdrawbars supports a row of spider wheels rearwardly adjacent the mainframe. A second set of assemblies with longer drawbars supports a secondrow of spider wheels substantially rearwardly of the first row. Thewheels are run at an angle of approximately thirty degrees with respectto the direction of travel, with the wheels on one half of the machineangled the opposite direction as on the other half. The wheels of thetrailing row are generally centered between and angled oppositely tothat of the immediately preceding wheels of the forward row. The centerridge left untilled due to the tandem wheel configuration is tilledusing a special center arrangement. In the preferred embodiment, thiscenter arrangement includes an arm at the machine center line with twooppositely angled wheels. These two wheels, as well as the two wheelslocated adjacent the machine center line in both the leading andtrailing rows are smaller than at least a majority of the remainingwheels of the machine to allow the machine to level the soil whileproviding good incorporation. To feather the effect of the angled wheelsat the ends of the machine, a small diameter wheel is located on theoutside of the outermost large diameter wheel so that the larger wheeleffectively holds the smaller wheel at a more shallow working depth. Theframe is smaller than at least most tandem wheel configurationimplements, and ridging and banding of chemicals are substantiallyeliminated. Most chemicals, and some small seed grains, can beeffectively incorporated at high speeds in a single pass with reduceddraft requirements. The unique configuration of spider wheels providesuniform incorporation capability across the entire width of the machinewithout banding of chemicals or ridging effects.

Each of the spider wheels includes a plurality of tines curvingrearwardly with respect to the forward direction of rotation and havinga concave front face for improved rotation and soil mixing action. Theopening between the teeth is kept at a maximum and is varied linearly toincrease only slightly from tooth root to the tip of the tooth tominimize wedging and permit the machine to work in severe residueconditions without collecting trash. The curvature of the tooth isestablished to utilize centrifugal force of the rotating wheel to expeltrapped trash.

The utilization of two spider wheels on a single drawbar helps to cancelsevere side forces. In addition, the U-shaped wheel support is somewhatresilient so that some of the side forces are absorbed without beingtransmitted to the drawbar and to the main frame. The overallarrangement of wheels provides a substantially balanced wheelconfiguration to eliminate any noticeable side forces on the frame.

These and other objects, features and advantages of the presentinvention will become apparent to those skilled in the art from thedescription which follows and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an implement constructed according to theteachings of the present invention and showing the general configurationof the spider wheels supported from the implement frame.

FIG. 2 is a rear perspective view of a portion of the left side of theimplement of FIG. 1.

FIG. 3 is a plan view of a spider wheel utilized with the implement ofFIG. 1.

FIG. 4 is a sectional view of the spider wheel taken substantially alongthe lines 4--4 of FIG. 3.

FIGS. 5a-5e are sectional views taken along lines 5a-5a through 5e-5e,respectively, of FIG. 3 and showing the shape of the tine along itslength by a plurality of cross sections rotated outwardly from the tine.

FIG. 6 is a sectional view of the hub portion of the spider wheel takensubstantially along the lines 6--6 of FIG. 3.

FIG. 7 is a plan view of the left side of the implement of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, there is shown a rotary incorporating implementindicated generally at 10 attached to a tractor 12 for forward movementF over a field wherein materials such as chemicals or seed grains are tobe incorporated into the soil. The implement 10 includes a main frame 14extending transversely to the forward direction F and having generallycentrally located hitch structure 16 adapted for connection to hitchstructure 18 on the towing vehicle 12 or alternately on a cartarrangement for pull-type operation behind another implement. The mainframe 14 includes a tubular beam 20 extending generally an equaldistance on either side of a center line 22 which bisects the implement10.

Bracket structure, indicated generally at 24, is connected to the aftface of the tubular beam 20 and supports a tandem arrangement of rotaryincorporating tools 28 and 29. The tools 28 and 29 are preferably spiderwheels arranged generally in two rows, a leading row 32 and a trailingrow 34. As best seen in FIG. 1, the leading row 32 includes a first setof spider wheels 28 located to the left of the center line 22 and also asecond set of spider wheels 29 located generally to the right of thecenter line 22. The spider wheels 28 and 29 are generally uniformlyspaced across the width of the machine with the spider wheels of thefirst set 28 supported for rotation about axes offset at an acute anglewith respect to the forward direction. The spider wheels 29 of thesecond set are similarly spaced but are mounted for rotation about axesoffset at an acute angle which is generally equal in magnitude butopposite in direction to that of the angle of the first set of wheels.The trailing row 34 of spider wheels 28 and 29 includes a third set ofspider wheels 29 which are located to the left of the center line 22 anda fourth set of wheels 28 which are located to the right of the centerline 22. The third and fourth sets of spider wheels 29, 28 are supportedfrom the main frame 14 behind the first and second sets, respectively,in trailing relation thereto and are mounted for rotation about axesoffset at an acute angle generally equal in magnitude to, but oppositein direction to, the acute angle of the leading first and second setsrespectively. The spider wheels 29, 28 on the trailing row 34 arearranged such that a fore-and-aft extending upright plane passingthrough the center of a given rear wheel will bisect the area betweenthe centers of the wheels 29, 28 immediately forward of the given wheelin row 32. The first and second sets of spider wheels 28, 29 arearranged to move dirt outwardly from the center line 22 while the thirdand fourth sets of spider wheels 29, 28 tend to move dirt inwardlytoward the center line. The spider wheels 28, 29 of the first row arespaced transversely such that a small strip of soil is left relativelyunworked between adjacent forward wheels as the implement 10 is towed inthe forward direction, but the rear spider wheels 29, 28 are generallycentered on the unworked strips to provide a complete overlap for goodsoil working and chemical mixing characteristics.

To prevent soil working and chemical mixing discontinuities in the areaaround the center line 22 of the implement caused by the oppositelyangled wheel arrangement, a special central arrangement indicated at 36is provided. In the preferred embodiment, the central arrangementincludes a first centrally located single spider wheel 39 supported at alocation offset slightly to the right of the center line 22 for rotationabout an axis substantially parallel to the axis of rotation of thespider wheels 29 in the first row. The single spider wheel 39 is offsetslightly rearwardly of the first row. A second centrally located singlespider wheel 38 is positioned rearwardly of the first single spiderwheel 39 and offset toward the opposite side of the center line 22slightly forwardly of the rear row 34 of wheels. The axis of rotation ofthe wheel 38 is offset at an acute angle generally equal to, butopposite in direction to, the angle of the first single spider wheel 39.The first spider wheel 39 will tend to move the soil from the centerline toward the right as viewed in the forward direction in FIG. 1. Thesecond spider wheel 38 will move the soil adjacent the center line inthe opposite direction. The innermost spider wheels, designated as 28a,29a of the front row 32 are located on either side of the center line 22and are offset transversely a sufficient distance to leave a small stripof unincorporated material. The innermost spider wheels 29d, 28d of thetrailing row 34 are offset outwardly of the innermost spider wheels 28a,29a, respectively, to move some of the soil and material thrownoutwardly by the wheels 28a, 29a back towards the center line 22.

Most of the spider wheels 28, 29 are of equal diameter. However, theinnermost wheels 28a, 29a, and 29d, 28d on opposite sides of the centerline 22 of the two rows of wheels are substantially smaller than thenext outwardly adjacent wheels 28, 29 and 29, 28, respectively. Also,the outermost wheels 28b and 29b are also substantially smaller than theadjacent wheels 28 and 29 to reduce the amount of soil and materialthrown outwardly by the first row 32. The outermost wheels 28c and 29cof the trailing row 34 are made smaller than the next adjacent spiderwheels 28 and 29 to feather the effect of the angled wheels at the endsof the machine. The wheels 39, 38 are also smaller in diameter. Thearrangement 36 of smaller centrally located wheels 28a, 29a, 29d, 28d,38 and 39 eliminates center ridges while providing uniform incorporationof chemicals in the soil worked by the center of the machine.

As best seen in FIG. 1, the spider wheels 28 and 29 in the respectivesections of the forward row 32 are uniformly spaced and supported inpairs from the main frame 14 by vertically rockable wheel supportassemblies 42 and 43. The wheels 29 and 28 in the respective sections ofthe trailing row 34 are supported by wheel support assemblies 44 and 45which are also rockably connected to the main frame 14. A centrallylocated wheel support assembly 46 carries the spider wheels 38 and 39between the innermost wheel assemblies 42a and 43a of the first row 32and between the innermost wheel assemblies 44d and 45d of the second row34. The wheel support assemblies 42-46 are connected for rocking about atransversely extending pivot tube 48 (FIG. 2) which is attached to theaft face of the tubular beam 20 of the main frame 14 by the brackets 24.Vertically adjustable gauge wheel assemblies 54 and 56 located on theleft and right outer ends, respectively, of the tubular beam 20generally locate the beam in the proper position when the hitch 18lowers the main frame 14 to the field working position.

The wheel support assemblies 43 and 45 on the right-hand side of theimplement 10 are substantially the mirror images of the wheel supportassemblies 42 and 44, respectively, on the left-hand side of theimplement. Therefore, only those assemblies on the left-hand side of themachine will be described in detail here. Referring to FIG. 2, each ofthe brackets 24 includes an upright and rearwardly openingchannel-shaped bracket assembly 62 supported against the back face ofthe beam 20 by a U-bolt 64. The lower end of the channel-shaped assembly62 extends below the bottom of the tubular beam 20 and is apertured at66 to receive the pivot tube 48. The wheel support assembly 44 includesa fore-and-aft extending arm 68 which is generally rectangular in crosssection. A transversely extending hollow, cylindrical member 72 iswelded to the bottom of the arm 68 rearwardly of the forwardmost end ofthe arm. A gusset 74 is connected between the side of the arm 68 and thetop of the cylindrical member 72. Adjacent brackets 24 are transverselyspaced to receive the cylindrical member 72 therebetween, and the pivotshaft 48 is extended through the cylindrical member 72 to pivotallyconnect the arm 68 to the main frame 14. The forward end of the arm 68extends under the bottom of the beam 20 to provide a transport stop forthe arm when the frame 14 is lifted from the field working to thetransport position.

An inverted U-shaped member 78 includes a transversely extending upperbight portion 82 which is connected adjacent its left-hand side to theaft end of the arm 68. Side legs 84 and 86 extend downwardly from thebight portion 82 to lower ends which support axle shafts 90 and 92. Eachshaft in turn supports a hub 94 for rotation on a pair of bearings (notshown) spaced on the axle shaft. The hubs 94 are connected to the spiderwheels 29 by four bolts 96. The hubs 94 space the wheels from theirrespective side legs a sufficient distance for good trash clearance.

The wheel support assemblies 42 are constructed in a fashion similar tothat of the assemblies 44, and include an arm 98 connected to acylindrical member 102 and having a gusset 104. The pivot tube 48 isinserted through the cylindrical member 102 to connect the arm 98, forrocking vertically with respect to the main frame 14. The forward end ofthe arm 98 projects slightly forwardly of the pivotal axis of the pivottube 48 but yet clears the bottom of the beam 20. A transport stop shaft106 is connected between adjacent brackets 24 above the forward end ofthe arm 98 to limit the downward rocking of the arm as the main frame 14is lifted to the transport position. An inverted U-shaped member 108includes a transversely extending upper bight portion 112 withdownwardly directed left and right side legs 114 and 116, respectively.Axle shafts 120 and 122 are connected to the lower ends of the side legs114 and 116, respectively, and rotatably support hubs 124 of the spiderwheels 28 for rotation about generally parallel axes which are angled sothat soil is directed outwardly from the center line 22 of the machine.The axle shafts 90 and 92 of the assembly 44 are angled so that soil isdirected inwardly toward the center line 22 of the machine.

As best seen in FIG. 2, the rear U-shaped members 78 are offset inwardly(that is, to the right as viewed in FIG. 2) with respect to thesupporting arm 68. The forwardmost members 108 are also offset inwardlyin the same direction. The spider wheels 29 on the rear members 78 arelocated on the inside of (to the right of) the upright side legs 84 and86 while the spider wheels 28 on the members 108 are located on theopposite or outward sides of the side legs 114 and 116. The outermostwheel 28 on the assembly 42 therefore is positioned centrally withrespect to the spider wheels 29 located on the next outwardly adjacentassembly 44, while the innermost wheel 28 of the assembly 42 is locatedbetween the adjacent wheels 29 of the adjacent assemblies 44.

Down pressure spring assemblies 132 and 134 are connected between theframe 14 and the wheel support assemblies 42 and 44 to bias thecorresponding wheels 28 and 29 into engagement with the soil. Theassembly 132 includes a spring 136 having one end connected by a bracket138 to the underside of the arm 98 and an opposite end connected to aspring retaining rod 140 which extends through the lower portions of thebrackets 24 below the pivot tube 48. The assembly 134 includes a spring146 having one end connected to a bracket 148 via a turnbuckle 150 andan opposite end connected to the spring retaining rod 140. The spring136 is selected to provide approximately three times the down pressureon the forward row 32 of wheels 28 as compared with the down pressure onthe rear row 34 of wheels 29. An additional spring 136 may be mountedbetween the bracket 138 and the spring retaining rod 140 to provide thenecessary down pressure, while in many situations it is possible toeliminate the spring 146 for the rear support assemblies 44 since theweight of the assemblies may be adequate without further bias to providethe necessary down pressure on the wheels 29.

The innermost wheels 28a, 29a (FIG. 1) on the wheel support assemblies42a and 43a, respectively, and the innermost wheels wheels 29d, 28d onassemblies 44d, 45d, respectively, on either side of the center line 22are substantially smaller than the outermost wheels on the sameassemblies, and therefore the outermost wheels tend to limit the depthof penetration of the innermost wheels to reduce the amount of dirtthrown by the innermost wheels. The smaller depth limited wheels alsoprovide more of a combing action as the tines move transversely throughthe soil.

The centrally located single spider wheels 38 and 39 are supported on anintermediate length arm 158 connected to the pivot tube 48 insubstantially the same manner as the arms 68. A down pressure springarrangement similar to that shown at 134 for the arm 68 may also beutilized. The forward spider wheel 39 is connected to the lower end of aside leg (not shown) which is connected near the central portion of thearm 158 and supports the wheel 39 for rotation about an axis generallyparallel to the axis of rotation of the spider wheels 29 on theassemblies 43. The rear single spider wheel 38 is connected to the lowerend of a second side leg which is located to the left of and rearwardlyof the first side leg. The lower end of the rear side leg supports thewheel 38 for rotation about an axis generally parallel to the axis ofrotation of the spider wheels 28 on the assemblies 42. The net outwardflow of dirt from the area around the center line 22 caused by theoutwardly angled and generally smaller diameter spider wheels 28a, 29a,38 and 39 substantially matches the net inward flow produced by thespider wheels 28, 28d and 29, 29d of the assemblies 44d, 45d locatedadjacent the center line 22. The smaller outermost spider wheels 28b and29b of the first row 32, which are also limited in depth of penetrationby the adjacent larger diameter spider wheels 28 and 29 supported on theassemblies 42b and 43b, respectively, tend to reduce the amount of dirtthrown outwardly at the ends of the first row 32. The two outermostwheels 29 and 29c of assembly 44c, and 28 and 28c of assembly 45c on thetrailing row 34 of wheels are both located transversely outwardly of thecorresponding forward wheels 28b and 29b to provide a net inward flowfrom row 34 which is generally equal to the net outward flow from row32. The large diameter wheels 28 and 29 of the assemblies 45c and 44c,respectively, effectively hold the smaller corresponding wheels 28c and29c at the outermost ends of the implement at a more shallow workingdepth to provide a combing action which feathers the effect of theangled wheels at the ends of the machine.

The wheels 28a, 29a are spaced transversely to permit some of thematerial that is to be incorporated into the soil to go through thecenter of the machine undisturbed. By reducing the size of the wheels28a, 29a, the material that is disturbed is not thrown outwardly fromthe center as far as it would be if the larger wheels 28 and 29 wereused. The wheels 39, 38 mix the strip left undisturbed by the forwardwheels 28a, 29a causing the strip of material to be split outwardly, butbecause the wheels 39, 38 are also relatively small in diameter, most ofthe soil and material does not move outwardly beyond the trailing wheels29d, 28d. However, the wheels 29d, 28d are also smaller in diameter toboth permit some of the soil and material moved by the forward wheels28a, 29a to go outwardly of the wheels 29d, 28d. The widely spaced,smaller diameter wheels open the area between the sets of wheels in therear row 34 to substantially eliminate hilling. The arrangement of thesix smaller diameter wheels 28a, 29a, 39, 38, 29d and 28d thuseliminates hilling while assuring that enough material to beincorporated remains adjacent the central area of the machine for auniform incorporation pattern. It was only after considerableexperimentation and testing with numerous wheel patterns that thepattern of FIG. 1 was devised which provides not only a level seed bedwithout ridges or loss or gain of dirt in a given area, but also uniformincorporation characteristics across the entire width of the machinewithout noticeable side forces acting on the frame 14.

The general construction of the wheel assembly 44c (and therefore theassembly 45c which is generally the mirror image of 44c) issubstantially identical to that of the assembly 44 with the exception ofthe outer axle 90c (FIG. 7) which extends through the lower end of theside leg 84 and supports the smaller diameter spider wheel 29c outwardlyof the side leg 84. The construction of the forward wheel assembly 42b(and therefore 43b) is substantially identical to that of theconstruction of the assemblies 42 (43) with the exception that theoutermost spider wheel 28b (29b) is substantially smaller than thecorresponding inner spider wheel 28 (29). Likewise, the assemblies 42aand 44d are similar to the assemblies 42 and 44, only the inner wheels28a and 29d are smaller.

The spider wheels are substantially larger and designed differently thanconventional rotary hoe spider wheels to provide better rolling action,soil and chemical (or other material) mixing action, and better cleaningaction in trashy conditions than at least most previously availablespider wheels for rotary hoes. The spider wheels 28, which aredesignated left-hand spider wheels because they typically move soil fromthe right to the left, are substantially the mirror image of the spiderwheels 29, designated as right-hand wheels since soil is moved towardthe right. The smaller spider wheels 28a-d and 38 are constructedsubstantially identically to each other and in a similar fashion to thewheels 28 but having a diameter substantially smaller than the wheels28. The wheels 29a-b and 39 are substantially identical to each otherand are similar to the wheels 29 but are substantially smaller indiameter than the wheels 29. Therefore, since the wheels are constructedwith similar principles, only the larger left-hand spider wheel 28 willbe described in detail here, it being understood that the right-handwheels 29 are mirror images of the wheels 28, and the smaller wheels onthe ends and central portion of the implement are generally smallerversions of the larger wheels, except for the cross section of the tineswhich remain substantially identical in size to that of the largerwheels to retain tine strength.

Referring to FIGS. 3-6, the wheel 28 includes a hub portion 172 with aplurality of tines 174 extending radially outwardly from the hub portionand curving rearwardly with respect to the forward direction of rotation(arrow) with a general radius of curvature which is substantiallysmaller than the radius of the wheel 28. The tine 174 includes arearwardly directed blunt face 176 and a concave soil working front face178 opposite the back face 176. The back face 176 and front face 178converge at an acute angle (FIG. 5) to define a curved side edge 180. Arelatively flat side 182 is located opposite the edge 180 and liesgenerally on the wheel plane designated at 184. The front face 178includes a forwardly directed lip portion 186 located adjacent the side182 for improved soil throwing and mixing action. The side edge 180 liessubstantially on a radius of curvature R₁ centered at a location nearthe root of the rearwardly adjacent tine 174. The radius of curvature R₂of the rear portion of the tooth corresponding to the lip 186 isapproximately equal to R₁, but the center of the radius R₂ is locatedradially outwardly of the hub portion 172 behind the rearwardly adjacenttine 174. At a central location designated at 187 in FIG. 3, thecurvature of the rear portion of the tooth decreases to a radius R₃substantially greater than the radius R₁ and R₂. The center of theradius of curvature R₃ is located on the second rearward tine slightlyradially outwardly of the hub portion 172. The particular constructionof the tines 174 provides a very open gullet portion indicated generallyat 189 which is substantially U-shaped, and wherein the distance betweena given tine and the rearwardly adjacent tine decreases only slightlyfrom the end of the tine toward the hub to reduce wedging of trash andfacilitate expulsion of trash by centrifugal force. As is evident fromFIG. 3, as a tine 174 is leaving the ground the gullet area between thattine and the next rearward tine opens substantially downwardly. Theouter edge of the hub 172 defines a relatively straight inner gulletarea 190 connected to the rear portion of the tine 174 by a relativelylarge radius at 192, and to the edge 180 by a slightly smaller radius194 to further reduce possibility of wedging. The area 190 is sharpenedto help cut through trash. The area 190 extends from the edge 180 at thebase of a given tine 174 diagonally (FIG. 6) to the lip portion 186 atthe base of the next forwardly adjacent tine 174. The curved edge 180continues inwardly to a center axle-hub receiving portion 198 which isapertured at 200 to receive the bolts 96 for mounting. The soil workingsurface 178 is generally continuous into the hub portion 172 andterminates at the portion 198. Cavities are formed at areas 204 toreduce the amount of material necessary to fabricate the wheel 28.

The tine cross section, which is best illustrated in FIG. 5 whereinvarious sections along the length of the tine are rotated ninety degreesoutwardly from the radius R₁ at that location, increases in thicknesstoward the base of the tine. The back face 176, which first engages thesoil, forms a relatively flat angle with the horizontal; the angle ofintersection of a line 210, parallel to the axis of rotation of thewheel 28, and the back face 176 is preferably thirteen degrees or less.By way of example, the angle between the line 210 and the face 176 isten degrees at section 5a, nine degrees at section 5b, ten degrees atsection 5c, thirteen degrees at section 5d and eleven degrees at section5e. The angle of the soil working surface 178, adjacent the edge 180,with respect to a line parallel to the wheel plane 184 increases fromabout thirty-seven degrees at the base of the tine to approximatelyfifty-five degrees near the tip of the tine. By way of example, theangle between the line 184 in FIG. 5 and the surface 178 adjacent theedge 180 is about thirty-seven degrees for section 5a, forty-threedegrees for section 5b, forty-five degrees for section 5c, fifty degreesfor section 5d and fifty-five degrees for section 5e. The tine 172includes an outermost tip portion 212, with the rear face 176 at the tip212 forming an angle of approximately twenty-one degrees with a planeextending perpendicularly to the wheel plane 184 and passing through theoutermost portion of the edge 180. The above-described tine constructionnot only provides aggressive mixing and soil throwing action but it alsoprovides a large effective profile on the tine lowermost in the soil topower the wheel for good rotation and entry of the relatively blunt backside 176 into the soil. As the tines 174 rotate in the soil about animage offset with respect to the forward direction, the tines movelaterally in the soil in the direction of the edge 180, moving some dirtand chemicals in the same general direction while permitting some of theremaining dirt and chemicals to slide between the tines. The large hubportion 172 provides depth control to prevent the wheels from actinglike solid disks and reducing mixing action.

In the preferred embodiment, the wheel 28 is substantially larger indiameter than a conventional rotary hoe wheel, and no more than tentines 174 are uniformly spaced about the hub to provide good clearanceand trash flow characteristics between the adjacent tines. In thepreferred embodiment, the wheels 28 (and 29) are approximately 500 mm indiameter. The smaller wheels at the ends and central locations on theimplement are at least approximately ten percent smaller, orapproximately 450 mm in diameter. The diameter of the hub portion 172 isslightly larger than half the diameter of the wheel. For example, thewheel 28 has a hub diameter of approximately 280 mm. Also, by way ofexample, the radii R₁ and R₂ are preferably slightly less than half theradius of the wheel while the radius R₃ is substantially greater thanhalf the radius of the wheel. In the preferred embodiment, R₁ and R₂ are120 mm and R₃ is 170 mm. Also, in the preferred embodiment, the wheelaxes are angled thirty degrees with respect to the transverse direction,and the spacing between adjacent wheels on each section of the machine10 is approximately one half the wheel diameter, or approximately 250mm. The spacing between the innermost wheels 28a and 29a of the firstrow 32 is approximately three-fourths of the diameter of the largerwheels or approximately 380 mm. The center of rotation of the singlespider wheel 39 is offset to the right of the center line 22 by adistance approximately equal to one-eighth of the diameter of the largewheel. The single spider wheel 38 is offset in the opposite direction anequal distance. Therefore, in the example given, the transverse spacingbetween the wheel centers of the wheels 38 and 39 is approximately 120mm to provide sufficient overlap of the wheels to assure that the soiladjacent the center line is adequately worked.

In the preferred embodiment, approximately 220 pounds of down pressureare provided on each wheel of the leading row 32 while the wheels of thetrailing row 34, working primarily in soil that has been previouslyloosened by the first row 32, have a down pressure of approximately onethird that of the wheels of the first row. The down pressure on each ofthe rear wheels is approximately sixty-five pounds.

The rear row 34 is spaced a substantial distance behind the forward row32, preferably such that the forwardmost extremities of the wheels inthe trailing row 34 are at least spaced by a distance equal to thediameter of the large wheels, or approximately 500 mm, from the rearmostextremities of wheels on the forward row 32. This configuration providesgood trash clearance between the rows and also permits the positioningof the single spider wheels 38 and 39 adjacent the center line 22between the rows 32 and 34 without trash flow problems.

During mounting of the shorter assemblies 42 to the frame 14, the stopshaft 106 may be removed from the brackets 24 for assembly with thesprings 136 in a completely relaxed state. After the springs 136 areattached between the brackets 138 and the spring retaining rod 140, theimplement may be lowered to tension the spring and bring the forward endof the drawbar 98 to a position below that wherein the stop shaft 106may be inserted. If the springs 146 are utilized on the longer arms 68,the turnbuckle 150 may be adjusted to also permit assembly of the wheelsupport assemblies 44 and 45 to the frame 14 with the springs 146 in theuncompressed state.

The side legs 114, 116 and 84, 86 provide resiliency to absorb some ofside loading resulting from the angled spider wheels. Mounting thewheels in pairs from the arms 68 and 98 not only reduces the cost andcomplexity of the machine and provides good ground contour following notavailable in large gang arrangements, but also helps to reduce theamount of side loads from the wheels that are transferred to the mainframe 14. The generally symmetrical pattern of the wheel configurationabout the center line 22 reduces the moments acting to move the tractor12 away from the forward direction to a neglibible amount.

Having described the preferred embodiment, it will be apparent thatmodifications can be made without departing from the scope of theinvention as defined in the accompanying claims.

We claim:
 1. A rotary incorporating implement adapted for connection toa towing vehicle for forward movement over the soil to incorporatematerial therein, said implement comprising:a transversely extendingmain frame having first and second transverse portions with first andsecond outer ends, a first set of rotary spider wheels, means forsupporting the first set of spider wheels at spaced transverse locationsalong the first portion of the frame for rotation about axes offset atan acute angle in a preselected direction from the transverse, a secondset of spider wheels, means for supporting the second set of spiderwheels at spaced transverse locations along the second portion of theframe for rotation about axes offset at an acute angle in a directionopposite the preselected direction from the transverse, a third and afourth set of spider wheels, means for supporting the third and fourthsets from the main frame at locations behind the first and second sets,respectively, in trailing relation thereto, the wheels of said third andfourth sets mounted for rotation about axes offset at an acute angleopposite in direction to the acute angle of the leading first and secondsets, respectively, and wherein the first and second sets of spiderwheels include forward innermost spider wheels transversely spaced withrespect to each other to provide an unincorporated strip of materialtherebetween, and wherein the second and third sets of spider wheelsinclude rear innermost spider wheels spaced transversely outwardly ofthe forward innermost spider wheels, and means for working theunincorporated strip of material and directing portions of the striptowards the rear outermost spider wheels comprising a first centrallylocated spider wheel, and means for supporting said centrally locatedspider wheel between the first and second sets for rotation about anaxis offset at a first angle from the transverse; and a second centrallylocated spider wheel, and means for supporting said second centrallylocated spider wheel rearwardly of the first centrally located spiderwheel for rotation about an axis offset at a second angle from thetransverse, said second angle being opposite in direction to said firstangle.
 2. The invention as set forth in claim 1 wherein at least most ofthe rotary spider wheels of the sets of spider wheels are equal indiameter, and wherein said centrally located spider wheels and saidforward and rear innermost spider wheels are substantially smaller indiameter than said most of the rotary spider wheels.
 3. The invention asset forth in claim 1 wherein the means for supporting the spider wheelsinclude means supporting the spider wheels in pairs for reducingtransfer of side forces, acting on said wheels as the implement is towedforwardly over the soil, to the main frame.
 4. The invention as setforth in claim 1 including first and second means for biasing the firstand second sets, and third and fourth sets, respectively, of wheelsdownwardly into the soil, said first means biasing the first and secondsets downwardly with substantially greater force than said second meansbiases the third and fourth sets.
 5. The invention as set forth in claim1 wherein the wheel centers of the spider wheels of the third and fourthsets lie on fore-and-aft extending upright planes generally centeredbetween the wheel centers of the forwardly adjacent spider wheels of thefirst and second sets.
 6. The invention as set forth in claim 3 whereinthe fore-and-aft spacing between the first and third, and the second andfourth sets of spider wheels is substantial compared to the diameter ofthe wheels so that the forwardmost extremities of the rearwardly locatedwheels of the third and fourth sets are substantially rearward of therearwardmost extremities of the adjacent wheels of the first and secondsets, and wherein the first and second centrally located spider wheelshave wheel centers located behind the wheel centers of the first andsecond sets and forwardly of the wheel centers of the second and thirdsets, respectively.
 7. The invention as set forth in claim 1 wherein themain frame comprises a tubular beam, and including drawbar means forattaching the spider wheels to the beam, said drawbar means comprising aplurality of fore-and-aft extending drawbars, means pivotally connectingthe forward end of each drawbar to the beam for rocking vertically abouta transverse axis, means for urging the drawbar downwardly including aspring connected between at least some of the drawbars and the beam, atleast one elongated transverse member, means selectively attaching themember to the main frame adjacent the forward end of said at least oneof the drawbars for contacting the drawbar to limit the downward rockingthereof when said transverse member is attached while permittinggenerally unrestricted downward movement when removed to permit thespring to reach a completely relaxed state thereby facilitating assemblyof the drawbar means to the main frame, and means rotatably mounting thespider wheels to the aft ends of the drawbars.
 8. The invention as setforth in claim 1 including drawbar means having fore-and-aft extendingdrawbars for supporting the wheels in two parallel rows, said drawbarmeans including an inverted U-shaped bracket having a bight portionconnected to the aft end of the drawbar, and two transversely spacedupright side legs each having a lower end, and axle means connected tothe lower end of each side leg and supporting a single one of saidspider wheels for rotation.
 9. A rotary incorporating implement adaptedfor connection to a towing vehicle for forward movement over the soil toincorporate material therein, said implement comprising:a transverselyextending main frame having a first and second transverse portions withfirst and second outer ends, a first set of rotary spider wheels, meansfor supporting the first set of spider wheels at spaced transverselocations along the first portion of the frame for rotation about axesoffset at an acute angle in a preselected direction from the transverse,a second set of spider wheels, means for supporting the second set ofspider wheels at spaced transverse locations along the second portion ofthe frame for rotation about axes offset at an acute angle in adirection opposite the preselected direction from the transverse, athird and a fourth set of spider wheels, means for supporting the thirdand fourth sets from the main frame at locations behind the first andsecond sets, respectively, in trailing relation thereto, the wheels ofsaid third and fourth sets mounted for rotation about axes offset at anacute angle opposite in direction to the acute angle of the leadingfirst and second sets, respectively, wherein the first and second setsof spider wheels are angled inwardly toward each other to provide a netoutward flow of soil and the third and fourth sets of spider wheelsinclude transversely outmost wheels defining the outermost soil workingportion of the implement, and means for limiting the amount of soilmoved by said outermost wheels relative to the adjacent spider wheels onthe respective third and fourth sets, wherein the outermost wheelscomprise spider wheels having a smaller diameter than the correspondingadjacent spider wheel and including means supporting each said outermostspider wheel and the corresponding adjacent spider wheel from the framefor vertical movement together to limit the depth of penetration of saidoutermost spider wheel relative to said corresponding next adjacentspider wheel.
 10. The invention as set forth in claim 9 wherein bothsaid outermost spider wheel and said corresponding adjacent spider wheelare located laterally outwardly of the corresponding outermost spiderwheels of the respective first and second sets.
 11. The invention as setforth in claim 10, wherein said corresponding outermost spider wheels ofthe first and second sets are substantially smaller than said most ofthe spider wheels.
 12. In a framed rotary incorporating implement forincorporating material into soil, said implement having a plurality oftransversely spaced spider wheels; means supporting the spider wheelsfrom the frame in two parallel fore-and-aft spaced rows for rotation inthe soil about axes offset from the transverse direction, wherein thetwo rows define an intermediate area wherein, in both the first row andthe second row, the axes of two adjacent spider wheels are offset atopposite angles with respect to the transverse to thereby cause adiscontinuity in the soil moving and material incorporatingcharacteristics in an area surrounding said adjacent spider wheels; andmeans for working the soil located in the intermediate area to provideuniform incorporation in said area comprising first and secondadditional spider wheels, means for supporting the first spider wheelgenerally between and slightly rearwardly of said adjacent spider wheelsof the first row for rotation in the soil about an axis offset in afirst direction with respect to the transverse, and means for supportingthe second spider wheel generally between and slightly forwardly of saidadjacent spider wheels of the second row for rotation in the soil aboutan axis in a direction with respect to the transverse opposite to thefirst direction.
 13. The invention as set forth in claim 12 furthercomprising means for limiting the depth of penetration of each of saidadjacent spider wheels of the first row with respect to the immediateoutwardly adjacent spider wheel of the first row.
 14. The invention asset forth in claim 12 wherein said first and second additional spiderwheels are substantially smaller in diameter than at least most of saidplurality of spider wheels and said adjacent spider wheels of the firstrow are also substantially smaller in diameter than at least most ofsaid plurality of spider wheels.
 15. The invention as set forth in claim13 wherein the means for limiting the depth of penetration includesbracket means for supporting one of said adjacent spider wheels of thefirst row and the corresponding immediately outwardly adjacent spiderwheel of the first row for vertical movement together, and wherein saidone of said adjacent spider wheels has a diameter substantially greaterthan the diameter of said corresponding outwardly adjacent spider wheel.16. A rotary incorporating implement adapted for connection to a towingvehicle for forward movement over soil, said implement comprising:atransverse frame; a plurality of transversely spaced spider wheelassemblies, each assembly including a fore-and-aft extending drawbarpivotally connected at its forward end to the frame for rockingvertically, a wheel support having two transversely spaced side legs andconnected to the aft end of the drawbar, said side legs extendingdownwardly from the drawbar to lower ends, a spider wheel connected tothe lower end of eac h side leg for rotation about a wheel axis as theimplement is towed forwardly over the soil, said wheel axis offset at anacute angle to the forward direction, wherein the wheel axis of thewheel on one of the legs is offset from and independent of, butgenerally parallel to, the wheel axis of the wheel on the other leg,said side legs being resilient to absorb side loading from the angledspider wheels, and said drawbars are generally two different lengths andspaced along the width of the frame to define a leading and a trailingrow of spider wheels.
 17. The invention as set forth in claim 16comprising a transversely outermost spider wheel assembly, said assemblyfurther including in addition to the spider wheel on each of the sidelegs, a third spider wheel extending outwardly from the spider wheel onthe outermost leg and supported by said outermost leg for rotation aboutan axis generally coinciding with the axis of said spider wheel on theoutermost leg.
 18. The invention as set forth in claim 17 wherein saidthird apider wheel on the outermost assembly has a radius substantiallysmaller than the radius of the adjacent spider wheel to thereby reducethe depth of penetration of said third spider wheel relative to saidadjacent wheel.
 19. The invention as set forth in claim 16 wherein thespider wheel assemblies comprise at least two sets of assemblies havingcorresponding drawbars of first and second preselected lengths, saidsecond length being substantially greater than that of the first length,said leading and trailing rows of wheel assemblies being parallel toeach other, and wherein the offset angles of the spider wheels of theleading row are generally opposite to that of the corresponding spiderwheels of the trailing row.
 20. The invention as set forth in claim 19wherein the wheel assemblies of the first row position along one half ofthe frame have spider wheels with offset angles equal in magnitude to,but opposite in direction to, the offset angles of the spider wheels onthe wheel assemblies of the first row positioned along the other half ofthe frame, wherein said spider wheels of the first row are angled towardthe center of the implement to thereby cause soil to flow outwardly withrespect to the center.
 21. The invention as set forth in claim 20wherein the wheel assemblies corresponding to the leading row of wheelscomprise two innermost assemblies located on opposite sides of thecenter of the main frame, said implement further comprising wheel meanssupported from the frame at a central location for rotation generallybetween the rows and between the two innermost assemblies for workingthe soil adjacent the center of the frame.
 22. The invention as setforth in claim 21 wherein the innermost spider wheel on each of the twoinnermost assemblies is substantially smaller than the outermost spiderwheel on said assembly.
 23. The invention as set forth in claim 22wherein said wheel means includes a centrally located spider wheel. 24.The invention as set forth in claim 23 wherein said wheel means furthercomprises a second centrally located spider wheel supported for rotationfrom the frame rearwardly of the first-mentioned centrally locatedspider wheel, said centrally located spider wheels having wheel axesoffset at acute angles to the transverse direction to work the soilbetween said innermost wheel assemblies.
 25. The invention as set forthin claim 24 wherein said first-mentioned and second centrally locatedspider wheels, and the innermost spider wheels on said two innermostassemblies are substantially smaller than at least most of the remainingspider wheels on the implement and are angled to move soil outwardlyfrom the center of the implement.
 26. The invention as set forth inclaim 21 wherein the wheel assemblies corresponding to the trailing rowof wheels include two innermost wheel assemblies defining rear innermostspider wheels located on opposite sides of the center of the frame andspaced outwardly of the corresponding innermost wheels of the twoinnermost assemblies of the leading row.
 27. The invention as set forthin claim 26 wherein the wheel means includes wheels having wheel axesangled from the transverse for directing soil and material to beincorporated outwardly toward said two innermost wheels of the trailingrow.
 28. The invention as set forth in claim 27 wherein said innermostwheels of the leading row are transversely spaced to leave a relativelyundisturbed strip of soil adjacent the center of the frame, and saidwheel means generally splits said strip outwardly toward said innermostwheels of the trailing row.
 29. The invention as set forth in claim 20wherein the implement further comprises in the trailing row a laterallyoutermost soil working wheel defining an outermost working portion ofthe implement, and including means for feathering the soil workingeffect of said outermost portion to prevent ridging adjacent theoutermost portion.
 30. The invention as set forth in claim 16 whereinthe wheel support comprises an inverted U-shaped bracket having atransversely extending bight portion, said side legs extendingdownwardly from the bight portion, wherein two parallel rows of sidelegs are defined corresponding to the leading and trailing rows ofspider wheels, wherein the innermost wheel of one spider wheel assemblyfor one of the rows is located inwardly of the outermost wheel of theinwardly adjacent wheel assembly of the other of said rows.